If someone is trying to reduce expenses via solar the LAST thing they want to do is incure expenses of battery strings. They are not trying to install backup power, they are trying to lower their consumption from the grid. And giving back to the grid is a GREAT way to do that.
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Janice

If someone is trying to reduce expenses via solar the LAST thing they want to do is incure expenses of battery strings. They are not trying to install backup power, they are trying to lower their consumption from the grid. And giving back to the grid is a GREAT way to do that.

If someone is trying to reduce expenses via solar the LAST thing they want to do is incure expenses of battery strings. They are not trying to install backup power, they are trying to lower their consumption from the grid. And giving back to the grid is a GREAT way to do that.

For the individual and only as long as a small percentage of people make that choice. If everyone went to solar then there would be no need of any power on the grid when the sun is shining. Of course at night we would need lots of dirty fossil fuel plants as they are able to ramp up and down output on a dime.

I still think that for individual personal home use, solar power still doesn't cost in. By the time you have bought the panels, inverter, control gear, special meter to manage feed in rates, installed, assembled, and tested it, it is a lot of money. Are they safe from lightening strikes on the roof, will pigeon mess or dirt affect their performance, do they need cleaning maintenance? The average homeowner doesn't have a roof ladder. And in the UK, how many sunny enough days per year do we get?

The average home computer draws about 300W on its own, electric kettles run at 3000W, one bar electric fires are 1000W. A 250W panel wouldn't be worth installing. In my town there also planning regulations to be taken into consideration as well.

The following limits apply to standalone solar panels:

Should be no higher than four metres
Should be at least 5m from boundaries
Size of array is limited to 9 sq m or 3m wide and 3m deep
Only one stand alone solar installation is permitted.
If your house is in a conservation area and the panels are to be fitted to a building in your garden or grounds they should not be visible from the highway.

You try putting a wind turbine in your back garden - no chance! At present only commercial solar farms seem viable, estuary wave power is too untried, and onshore and offshore wind farms are having much controversy from the NIMBY's. Hydro electric is a good means of energy generation, and at present gives 1.3% into the UK energy mix, but is mainly confined to Scotland, nowhere else in England or Wales is suitable. We just don't have the California desert or Colorado rivers in the UK. but reducing our carbon footprint as much as possible by using renewables wherever we can, is a prime objective.

One day oil, gas, and coal will run out, there are finite reserves of those fuels. For us over here, the only long term way forward is to adopt nuclear power. Three Mile Island in 1979, was because of mechanical failures and inadequate training, Chernobyl in 1986, was because of design faults, and unsafe operating procedures, Fukushima in 2011 was caused by an earthquake followed by a tsunami, that knocked out the emergency generators for the cooling pumps, which were on the ground floor. Political inaction delayed salt water flooding, until it was too late to prevent meltdown.

Lessons from all those have been learnt, and we already have in service nuclear submarines containing power plants with a 30 year life, which are perfectly safe. We just need to scale them up a bit.

Chris no one is recommending a single panel on a home. The inverter would cost several times over the panel and it just would not make sense.

20 panels at a time? Now that could have a significant impact on someones electric bill. Keep in mind 1 watt*average peak sun*365/1000=KWH per year, typical life expectancy of the panels 20-30 years. At my current high end rate of approx $.33USD per KWH.. it is not hard to make a case for them.

Wind is another matter, and in urban/suburban areas it is difficult to place, though not impossible. There is of course the assumption when trying to get a permit that you want to install 5MW giant towers, when even a 300-500 watt(less than 5 ft diameter) could easily be installed on most roof tops with minimal to no bad effects on your neighbors.

Largest plant 20MW. Single nuclear plant 950-1300MW. I think you have a scale issue here. Also how long can this energy be stored before it all leaks away? Or are you attempting to deny friction. Heat storage has the same issues. Storage as gravity or chemical does not.

If you note the photos of that plant it appears to be approx. 5 acres.
Friction would be a factor on the flywheel storage, not an overwhelming factor but a factor. For heat storage it is a matter of insulation. a single LARGE object takes a long time to cool. converting to gravity(pumping liquids up I presume? or hoisting large objects to drop later?) does have waste energy involved as well. As does charging batteries(chemical).

... Which would hurt less: a global carbon price of $US20 now, or a $US100 carbon price in 2020?...

... If mitigation steps aren’t taken, the researchers say, global annual emissions by 2020 will reach 55 gigatons of CO2 each year. At that point, IIASA’s Keywan Riahi says, “you would need to shut down a coal power plant each week for ten years if you still wanted to reach the two-degree Celsius target”.

“Fundamentally, it’s a question of how much society is willing to risk,”...

If you note the photos of that plant it appears to be approx. 5 acres.
Friction would be a factor on the flywheel storage, not an overwhelming factor but a factor. ...

Those units operate in a vacuum and with magnetic levitation bearings that makes the friction losses negligible. Impressive stuff. Rather neat and effective.

You can even get them now for replacing large sized battery-backup UPSes.

Rather good and quite a game changer...

A few of orders of magnitude to small to be "a game changer" I mean, you aren't going to be able to store much energy when 5 of them fit on a single flat bed trailer.

I was looking for a total storage capacity for a unit but couldn't find it. I see the worlds largest plant was shown as 20MW, but that is load. Didn't say how long it could keep that up. Also it was being talked about for phase synchronization. That is only very momentary in comparison with storing several hours of energy for use when the sun don't shine.

Practical lesson. Gravity stores energy in moving a mass. A rotating object stores its energy in a moving mass. What is the weight of the water that is released by an hour for a medium hydroelectric dam? What is the weight limit of a single flatbed trailer? Are we getting the picture yet?